Can you tell me (sorry a bit too lazy to look) when you quick register a host, does it ask you for a group assignment? If so you could use the persistent group (hack) to create a host template with all of the settings you want by default for new hosts, then when you add the system to a template group, those settings will be copied to the newly registered host.
The other way I can think how to do this is create a mysql database trigger, to when a new host is added to the hosts table in mysql, the check box is checked in the database. I’m not really in favor of the second part, but it will work if all other choices fail. The template host/persistent group plugin it a bit cleaner approach.
